Unauthorized use of software is an important issue for a software developer. Therefore, as a method of preventing unauthorized use, such a scheme that software is “individualized” so that use thereof is permitted in a computer having a license and a copy of the software does not work in another computer has conventionally been proposed. Here, “individualization” means that an operation of software is prohibited or restricted in an environment where a parameter is different, by at least partially modifying the content configuring the software in accordance with such parameters as system information of hardware or user information.
Japanese Patent Laying-Open No. 11-024918 discloses, as an example of such a technique, a technique to “individualize” the software by using a MAC (Media Access Control) address. Specifically, Patent Document 1 discloses in paragraph [0025] recording of a MAC address of a target computer in software at the time of introduction of the software. Then, when the software is started, the MAC address of the computer is compared with the MAC address recorded in the software (see paragraph [0030]). If the MAC addresses do not match, start of the software is aborted (see paragraph [0031]).
According to such “individualization” of the software, once processing for software introduction is performed on certain hardware, even if a malicious user copies the software that has been introduced in the certain hardware to another hardware, the copied software does not operate on another hardware or the operation is restricted. Therefore, “individualization” of the software can serve as an effective measure against unauthorized use of the software.    Patent Document 1: Japanese Patent Laying-Open No. 11-024918